Fettmasse

Fettmasse is the total mass of adipose tissue in the body, typically expressed in kilograms or as a percentage of body weight. It includes essential fat, which is necessary for normal physiological function, and storage fat, which serves as an energy reserve.

Adipose tissue serves multiple roles. White adipose tissue stores energy in the form of triglycerides and acts as an endocrine organ, releasing hormones and cytokines such as leptin and adiponectin that influence metabolism and appetite. Brown adipose tissue, by contrast, burns energy to generate heat. The distribution and amount of fat mass influence health, energy balance, and metabolic function.

Measurement and estimation methods vary in accuracy and practicality. Common approaches include dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), skinfold thickness measurements, hydrostatic (underwater) weighing, and air displacement plethysmography (Bod Pod). MRI and CT can assess distribution of fat tissues but are less practical for routine use. No method is perfect; results can be affected by hydration, recent meals, and device calibration. In practice, DXA is widely used as a reference method for total fat mass and distribution.

Fat mass versus fat-free mass defines body composition. Fat mass divided by total body weight yields body fat percentage. Healthy ranges vary by age and sex; for example, men commonly range roughly from 8–19% and women from 21–33%, with athletes often lower within those ranges.

Clinical and practical relevance includes obesity assessment, monitoring of nutritional status, and evaluation in sports medicine. Excess Fettmasse is linked to increased risk of metabolic and cardiovascular diseases, while very low Fettmasse can indicate malnutrition or wasting.